KR102289877B1 - Method for controlling washing machine - Google Patents

Abstract

An outer tub containing water, an inner tub disposed in the outer tub to receive laundry and rotated about a vertical axis, a motor providing a rotational force, an outer shaft having a first hollow formed therein and rotating the inner tub; An inner shaft disposed in a first hollow, a pulsator disposed in the inner tank and coupled to the inner shaft, a planetary gear train that transmits the rotational force of the motor to rotate the inner shaft, and the inner shaft in the first hollow of the outer shaft is screwed and the outer shaft is spline coupled with the outer shaft to be lifted by rotation of the inner shaft, and when the inner shaft is rotated in the forward direction to reach the maximum lifting position, further lifting is restrained to rotate the outer shaft in the forward direction, and the inner shaft and a clutch for rotating the outer shaft in the reverse direction by stopping further descent when it is rotated in the reverse direction and reaches a predetermined maximum lowering position.

Description

How to control washing machine {METHOD FOR CONTROLLING WASHING MACHINE}

The present invention relates to a control method of a washing machine having a clutch system for connecting or disconnecting a washing shaft and a dehydration shaft.

In general, in a washing machine, an inner tub accommodating laundry is rotatably provided in an outer tub provided in a casing about a vertical axis, and a pulsator is provided in the inner tub to stir the water flow.

The washing machine includes a motor for driving the inner tub and the pulsator. The motor transmits power through a dual shaft structure having an inner shaft and an outer shaft, the inner shaft is a shaft that rotates the pulsator, and is directly connected to the motor, so that the pulsator always rotates when the motor is rotated However, the outer shaft is a shaft that rotates the inner tank, and is configured to be connected or disconnected from the inner shaft by a clutch.

That is, when the outer shaft and the inner shaft are connected by the clutch, the pulsator and the inner tub are rotated together, and on the contrary, when the outer shaft is separated from the inner shaft, the pulsator in the state where the inner tub is stopped only rotates.

Korean Publication No. 2000-0063005 discloses a clutch applied to a washing machine. The clutch is configured to include a plurality of gears and a lever for operating the gears, so that the structure is complicated, and a separate motor for operating the gear and the lever is required.

A washing machine with a simplified clutch structure is disclosed in Korean Publication No. 1993-0023530. The washing machine includes a washing shaft having a first rotating protrusion on an outer circumferential surface, a spin-drying shaft having a first locking protrusion on an inner circumferential surface, and a second blocking protrusion interposed between the spin-drying shaft and the washing shaft, and interfering with the first rotating protrusion on an inner circumferential surface A group is formed, and a switching part having a second locking protrusion interfering with the first locking protrusion is provided on the outer circumferential surface. When the second rotating protrusion is caught by the second locking protrusion by the rotation of the switching part, the spin-drying shaft is rotated.

Since only the washing shaft rotates until the spin-drying shaft is rotated, a mode in which only the washing shaft is rotated and a mode in which the washing shaft and the spin-drying shaft are rotated together can be selectively implemented.

However, in this structure, the protrusions formed on the washing shaft, the switching part and the dehydrating shaft interfere with each other to transmit torque, but it is not only practically difficult to ensure the strength or reliability of the protrusions, but also to transmit through the protrusions. There was a problem that the torque was limited and could not handle a large load. In addition, when only the washing shaft rotates alternately in both directions while the dehydration shaft is stopped, there is a problem in that collision noises between the projections are frequently generated.

The problem to be solved by the present invention is a washing machine having a clutch that connects (couples or connects) or disconnects the inner shaft and the outer shaft (the shaft that rotates the inner tub) while ascending and descending according to the rotation of the inner shaft that rotates the pulsator. In the present invention, there is provided a control method of a washing machine capable of precisely controlling the elevating range of the clutch.

When the clutch is positioned within a predetermined stirring control section, the inner shaft rotates in a state in which the connection with the outer shaft is released, but when the clutch is located at the upper or lower limit of the stirring control section, the inner shaft and the outer shaft are connected state, the inner shaft and the outer shaft are rotated together in the same direction. Therefore, when performing a stirring motion in which the pulsator rotates in both directions in a state in which the inner shaft is disconnected from the outer shaft, the lifting operation of the clutch is accurately performed so that the clutch does not reach the upper limit or the lower limit of the stirring control section. Another problem to be solved by the present invention is to provide a control method of a washing machine that can be controlled.

In particular, when the clutch reaches the upper limit or the lower limit of the stirring control section, shock and unnecessary noise may be generated due to interference between parts in the process of the clutch connecting the inner shaft and the outer shaft. Another problem to be solved by the present invention is to provide a method for controlling a washing machine that has been solved.

In the washing machine of the present invention, a clutch interposed between the inner shaft and the outer shaft is screw-coupled to the inner shaft, and is spline-coupled to the outer shaft. Since the spline engagement restricts the clutch from rotating relative to the outer shaft, the clutch is raised and lowered along the inner shaft when the inner shaft is rotated.

The clutch is raised and lowered within a predetermined range. That is, when the clutch reaches the preset maximum rising position, it cannot rise any more, and when it reaches the preset descending position, it cannot descend any more.

If the direction in which the inner shaft rotates so as to raise the clutch is referred to as the forward direction and the opposite direction is referred to as the reverse direction, the inner shaft rotates in the forward direction and the inner shaft continues to rotate in the forward direction even after the clutch reaches the maximum lifting position. As the clutch is no longer raised (ie, the clutch can no longer be rotated relative to the inner shaft), the clutch rotates integrally with the inner shaft, with the outer shaft being splined with the clutch. It rotates together because it is

Likewise, if the inner shaft continues to rotate in the reverse direction even after the inner shaft is rotated in the reverse direction and the clutch has reached the maximum lowered position, since the clutch can no longer be lowered (i.e., the clutch can no longer be lowered relative to the inner shaft) relative rotation), the clutch rotates integrally with the inner shaft, with the outer shaft also rotated.

The method of controlling such a washing machine includes a stirring mode in which the pulsator is relatively rotated with respect to the inner tub and a spin mode in which the pulsator and the inner tub are integrally rotated.

The stirring mode includes a reference position alignment step of rotating the motor in a first direction to align the clutch to a reference position, and a second direction (the first direction) of the motor in a state in which the clutch is aligned at the reference position. and a starting position alignment step of aligning the clutch to the starting position by rotating it in the opposite direction).

Here, the reference position may correspond to any one of the maximum descending position or the maximum ascending position. When the reference position is the maximum descending position, the first direction is a rotation direction of the motor when the inner shaft is rotated so that the clutch is lowered.

The starting position is set to correspond to any one of the upper and lower limits of the stirring control section. The upper limit of the stirring control section is spaced downward by a first distance from the maximum ascending position, and the lower limit of the stirring control period is spaced upward by a second distance from the maximum descending position.

In the starting position alignment step, the motor is rotated by a preset starting alignment angle in the second direction to move the clutch from the reference position to align it to the starting position.

Thereafter, the step of moving the clutch from the starting position to a target position corresponding to the other one of the upper and lower limits of the stirring control section is carried out, wherein the rotation of the motor is performed from the starting position to the target position. The rotation of the motor is controlled by the agitation control angle set according to the displacement of the clutch. The step of controlling the rotation of the motor so that the clutch returns from the target position to the starting position may be further carried out, and by repeating these steps, the clutch can repeat rising and falling within the stirring control section there is.

When it is detected that the clutch has reached a preset allowable position out of the stirring control section while the clutch is raised and lowered repeatedly, the reference position alignment step may be performed again.

Alternatively, when the set time elapses while the clutch is repeatedly raised and lowered, the reference position alignment step may be performed again.

The step of aligning the reference position may include controlling the motor to rotate in the first direction at a reference alignment angle set according to displacement of the clutch between the maximum rising position and the maximum descending position.

In the reference position alignment step, when the current value of the motor is greater than or equal to a preset first current value while the motor is rotating in the first direction, it is determined that the clutch has reached the reference position and braking the motor may include steps. The braking of the motor may be performed based on a current value of the motor sensed after a first set time has elapsed after the motor starts rotating in the first direction.

In the reference position alignment step, within a second set time after the motor starts to rotate in the first direction, the current value of the motor is a second current value corresponding to the current value when the motor is started, A third current value corresponding to a current value when the inner shaft and the outer shaft are connected when the clutch reaches the maximum rising position or the maximum falling position, and after the third current value is sensed, the inner shaft and the outer shaft and braking the motor by determining that the clutch has reached the reference position when a fourth current value corresponding to the current value when integrally rotated in the connected state is sequentially sensed.

The spin mode may include at least one of: rotating the motor in a forward direction when the clutch is positioned at the maximum rising position; and rotating the motor in a reverse direction when the clutch is positioned at the maximum descending position. includes the steps of

The washing machine may further include a planetary gear train rotated by the motor. The planetary gear train includes a ring gear fixed to an inner circumferential surface of the gear housing, a sun gear connected to a drive shaft of the motor, a pinion gear interposed between the sun gear and the ring gear, and meshing with the sun gear and the ring gear; , by rotatably supporting the plurality of pinion gears to rotate as the plurality of pinion gears revolve along the ring gear, coupled to the inner shaft, may include a carrier for rotating the inner shaft by the rotation.

The control method of the washing machine of the present invention is interposed between an inner shaft and an outer shaft, and is raised and lowered according to the rotation of the inner shaft, and by precisely controlling the elevation range of a clutch connecting or disconnecting the inner shaft and the outer shaft, the rotation of the pulsator It is possible to prevent the clutch from reaching the maximum rising position or the maximum falling position connecting the inner shaft and the outer shaft in the process of changing the direction.

Therefore, during agitation washing in which the pulsator rotates alternately in both directions, it is stably performed in a state in which the inner shaft and the outer shaft are disconnected. It has the effect of preventing the occurrence of interference or shock and unnecessary noise between parts due to connection).

1 is a longitudinal cross-sectional view of a washing machine according to an embodiment of the present invention.
FIG. 2 is an enlarged view of a part of the washing machine shown in FIG. 1 .
Figure 3 (a) schematically shows the operation of the planetary gear train when the pulsator is rotated relative to the inner tank, and Figure 3 (b) is the planetary gear train when the inner tank and the pulsator are rotated together The operation is schematically shown.
4 is a partially cutaway view of part "A" of FIG. 1, (a) shows the state in which the clutch is in the maximum descending position, and (b) shows the state in which the clutch is in the maximum ascending position. are doing
5 shows positions referenced for clutch position control.
6 is a block diagram illustrating a control relationship between main parts of a washing machine according to an embodiment of the present invention.
7 is a flowchart illustrating a method for controlling a washing machine according to an embodiment of the present invention.
8 shows the positions of the clutch in the process of initializing the position of the clutch.
9 shows detailed steps constituting the reference position alignment step.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

1 is a longitudinal cross-sectional view of a washing machine according to an embodiment of the present invention. FIG. 2 is an enlarged view of a part of the washing machine shown in FIG. 1 . Figure 3 (a) schematically shows the operation of the planetary gear train when the pulsator is rotated relative to the inner tank, and Figure 3 (b) is the planetary gear train when the inner tank and the pulsator are rotated together The operation is schematically shown. 4 is a partially cutaway view of part "A" of FIG. 1, (a) shows the state in which the clutch is in the maximum descending position, and (b) shows the state in which the clutch is in the maximum ascending position. are doing

1 to 4 , a washing machine according to an embodiment of the present invention includes an outer tub 1 containing water, and an outer tub 1 disposed in the outer tub 1 to accommodate laundry, and a vertical axis is the center of the washing machine. It includes an inner tub (2) rotated to, a pulsator (3) disposed in the inner tub (2), and a motor (10) for providing a rotational force.

The outer tub 1 is disposed in a casing (not shown) constituting the exterior of the washing machine. The outer shell 1 may be suspended in the casing by a support rod (not shown). A plurality of the support rods may be provided. When vibration is induced by the rotation of the inner tub 2, the outer tub 1 is raised and lowered along the support rod, and a suspension (not shown) or a damper (not shown) that cushions the lifting motion of the outer tub 1 is provided. can be provided.

The motor 10 is to provide power for rotating the pulsator 3 and the inner tank 2, it is possible to rotate forward and reverse. In addition, the motor 10 is capable of controlling the rotation direction and rotation speed. The motor 10 is preferably, but not necessarily limited to, a brushless direct current electric motor (BLDC).

The motor 10 is an outer rotor type in which a stator (not shown) in which an induction coil is wound is disposed in the center, and the rotor 11 is rotated around the stator. The rotor 11 may include a bottom part 13 and a ring-shaped side part 12 extending upwardly from the bottom part 13 . The driving shaft 10a of the motor 10 may be connected to the rotor hub 15 fixed to the bottom part 13 by the rotor bush 14 . A plurality of magnets (not shown) are provided on the inner circumferential surface of the side part 12 of the motor 10 in the circumferential direction, and the rotor 11 is rotated by the magnetic field acting between the stator and the magnet.

Referring to FIG. 6 , the speed control system of the BLDC motor 10 may include a speed controller 92 , a current controller 93 , a position detector 94 , and an inverter 95 . This speed control system is widely used for BLDC motor control.

When the motor 10 is a sensorless brushless DC electric motor, the position detector 94 includes a circuit for detecting the back electromotive force of the motor 10 . The controller 91 detects a zero crossing point (ZCP) in the waveform of the back electromotive force detected by the position detector 94 , and based on this, the position θ of the rotor (or the rotor 11 ) of the motor 10 . _m) can be detected. In addition, the position detector 94 may _{obtain the rotation speed (ω m} ^* ) by differentiating the position of the rotor. Alternatively, the position detector 94 may include a hall sensor for detecting the position or rotational speed of the rotor of the motor 10 .

The speed controller 92 outputs a command current I _dc ^* _{for following the command speed ω m} ^* applied from the control unit 91 . The speed controller 92 is a proportional-integral controller (PI controller) or a proportional-integral-differential controller (PID controller) that performs feedback control based _{on the current speed (ω m} ) applied from the position detection unit 94 . Proportional Integral Derivative controller).

The output torque of the motor 10 is proportional to the magnitude of the phase current, and the magnitude of the phase current is proportional to the input current I _dc of the inverter 95 . The current controller 93 generates a gating signal (PWM waveform) so that the input current I _{dc follows the command current I dc} ^* applied from the speed controller 92, and the inverter 95 according to the gating signal. is driven to rotate the motor 10 . Like the speed controller 92, the current controller 93 may be configured as a proportional-integral controller or a proportional-integral-differential controller.

A planetary gear train 8 is provided that receives the rotational force of the drive shaft 10a and converts the output to a preset speed or torque ratio to rotate the inner shaft 4 . The planetary gear train 8 will be described later in more detail.

The inner shaft 4 is coupled to the pulsator 3 . A fastening hole is formed in the center of the pulsator 3 , and a screw 23 passing through the fastening hole from the upper side may be fastened to the inner shaft 4 .

The outer shaft 9 is connected to the inner tub 2, and is in the form of a tubular shape having a first hollow through which the inner shaft 4 passes. A hub base 18 coupled to the bottom of the inner tub 2 may be provided at a lower side of the inner tub 2 . An opening is formed in the center of the bottom of the inner tub 2 , and the hub base 18 is fastened to the bottom of the inner tub 2 by passing a fastening member such as a screw or bolt through portions in contact with the periphery of the opening.

The hub base 18 rotates together when the outer shaft 9 rotates. The outer shaft 9 and the hub base 18 are engaged (or engaged). The outer shaft 9 and the hub base 18 may be spline coupled. Teeth constituting a spline may be formed on the outer surface of the outer shaft 9 . The hub base 18 has a disk shape as a whole, and a boss 18a through which the outer shaft 9 passes may be formed in the center thereof. On the inner circumferential surface of the boss 18a, meshing grooves engaged with the teeth may be formed.

The outer shaft 9 may protrude upward after passing through the boss 18a of the hub base 18 , and the protruding portion may be engaged with the nut 19 . In addition, the protruding portion may be provided with a sealer 24 for sealing the water contained in the inner tub 2 from entering the first hollow of the outer shaft (9).

A bearing housing 16 may be disposed below the outer tank 1 . The bearing housing 16 may be coupled to the bottom surface of the outer shell 1 . A bearing 26 supporting the outer shaft 9 may be provided in the bearing housing 16 .

When the motor 10 is rotated, the inner shaft 4 is always rotated. In contrast, in order for the inner tub 2 to rotate, the torque provided by the motor 10 must be transmitted from the inner shaft 4 to the outer shaft 9 , and this function is achieved by the lifting operation of the clutch 6 .

The clutch 6 is arranged between the inner shaft 4 and the outer shaft 9 . The clutch 6 is provided so as to be able to move up and down in a state engaged with the outer shaft 9 (or in a meshed state), and is screwed with the inner shaft 4 to the maximum descending position (in FIG. 4 ) by rotation of the inner shaft 4 . It can be raised and lowered between (a)) and the maximum ascending position (refer to (b) of FIG. 4).

The outer circumferential surface of the clutch 6 and the inner circumferential surface of the outer shaft 9 defining the first hollow are spline-coupled so that the clutch 6 can be lifted with respect to the outer shaft 9 . For example, at least one tooth (tooth, 61) constituting a spline is formed on the outer circumferential surface of the clutch 6, and at least one meshing groove corresponding to the at least one tooth 61 is formed on the inner circumferential surface of the outer shaft 9. (9r) is formed. The toothed grooves 9r are engaged with the teeth 61, respectively. Preferably, the cross section of the teeth constituting the spline is triangular, so that serrations engaging with each other may be formed on the outer circumferential surface of the clutch 6 and the inner circumferential surface of the outer shaft 9, respectively.

Since the teeth 61 formed on the outer circumferential surface of the clutch 6 mesh with the tooth grooves 9r formed on the inner circumferential surface of the outer shaft 9, the clutch 6 reaches the maximum rising position and is in a state in which it cannot rise any more. , when it reaches the maximum descending position and becomes in a state where it cannot descend any further, torque is transmitted to the outer shaft 9 through the clutch 6, and the clutch 6 and the outer shaft 9 rotate together. This will be described later in more detail.

The clutch 6 is screwed into the inner shaft 4 in the first hollow. A helix thread 41 is formed on the outer peripheral surface of the inner shaft 4 along the axial direction, and a thread (not shown) engaged with the thread 41 is formed on the inner peripheral surface of the clutch 6 . is formed That is, in the relationship between the inner shaft 4 and the clutch 6, the inner shaft 4 corresponds to an external thread, and the clutch 6 corresponds to an internal thread.

Since the outer circumferential surface of the clutch 6 is spline-coupled with the inner circumferential surface of the outer shaft 9, and the inner shaft 4 and the clutch 6 are screwed together, the inner shaft ( When 4) is rotated, the clutch 6 is raised or lowered according to the rotational direction of the inner shaft 4 while rotating relative to the thread 41 . Hereinafter, the rotational direction of the inner shaft 4 causing the clutch 6 to rise is referred to as a forward direction, and the opposite direction is defined as a reverse direction.

As for the clutch 6, when the inner shaft 4 rotates in the forward direction and reaches the maximum lifting position (refer to FIG. 4(b)), further upward movement is restrained. If the inner shaft 4 continues to rotate in the forward direction in a state where the lift of the clutch 6 is restrained, the outer shaft 9 also rotates in the forward direction.

Conversely, when the inner shaft 4 of the clutch 6 is rotated in the reverse direction to reach the maximum lowering position (refer to Fig. 4(a)), further lowering is restrained. If the inner shaft 4 continues to rotate in the reverse direction while the descent of the clutch 6 is restrained, the outer shaft 9 also rotates in the reverse direction.

At least one of the maximum raised position and the maximum lowered position of the clutch 6 may be defined by the thread 41 . That is, when the clutch 6 is rotated relative to the inner shaft 4 in the opposite direction to the upper end of the thread 41, the upward movement is restrained because the clutch 6 can no longer be rotated, and the clutch at this time The position of (6) becomes the maximum rising position.

Conversely, when the clutch 6 is rotated relative to the inner shaft 4 in the forward direction, reaching the lower end of the thread 41, the downward motion is restrained because the clutch 6 can no longer be rotated, and the clutch at this time The position of (6) becomes the maximum descending position.

On the other hand, alternatively, it is also possible to further include an upper stopper for restraining the rise of the clutch 6 and/or a lower stopper for restraining the lowering of the clutch 6 . For example, the bearing 27 interposed between the inner shaft 4 and the outer shaft 9 may be the upper stopper. It is also possible that a bearing for the lower stopper is further provided.

As another example, a bush or ring may be inserted into the inner shaft 4 , or a protrusion may protrude from the outer circumferential surface of the inner shaft 4 to constitute the upper stopper or the lower stopper.

Meanwhile, a region in which the clutch 6 moves within the first hollow formed in the outer shaft 9 may be provided outside the inner tub 2 . Furthermore, the region in which the clutch 6 is moved may be provided below the outer tub 1 . Since the area in which the clutch 6 is moved (or a space for installation or operation of the clutch 6) is not provided inside the inner tub 2, the pulsator 3 is installed in the inner tub ( 2) Can be placed on the floor.

The planetary gear train 8 transmits the rotational force of the motor 10 to rotate the inner shaft 4 . The planetary gear train 8 includes a sun gear 81 , a pinion gear 82 , a carrier 83 , and a ring gear 84 . The planetary gear train 8 rotates the inner shaft 4 by converting the torque input through the drive shaft 10a according to a predetermined gear ratio. The gear ratio may be determined according to the number of teeth of the sun gear 81 , the pinion gear 82 , and the ring gear 84 .

The planetary gear train 8 is disposed in the gear housing 5 coupled to (or axially connected to) the outer shaft 9 . The gear housing 5 is shaft-joined with the outer shaft 9 so that it rotates together when the outer shaft 9 rotates. The gear housing 5 has a boss 533 formed thereon. The lower end of the outer shaft 9 is coupled to the boss 533 so that the outer shaft 9 and the gear housing 5 are shaft-joined.

The gear housing 5 may include a lower housing 52 and an upper housing 53 . The lower housing 52 and the upper housing 53 are coupled to each other by fastening members such as screws or bolts. The lower housing 52 has a tubular shape as a whole to form a second hollow elongated in the vertical direction, and the driving shaft 10a is inserted into the second hollow.

The lower housing 52 may include a hollow shaft 521 forming the second hollow, and a lower flange 522 extending outward from the upper end of the hollow shaft 521 in a radial direction. Between the hollow shaft 521 and the drive shaft 10a, a bearing 33 for supporting the hollow shaft 521 and the drive shaft 10a to rotate relative to each other is interposed. In addition, a bearing 28 supporting the outer peripheral surface of the hollow shaft 521 is installed in the bearing housing 16 .

The upper housing 53 is disposed above the lower housing 52 . The upper housing 53 forms a predetermined accommodating space above the lower flange 522 , and the planetary gear train 8 is disposed in the accommodating space. The accommodating space is generally in the form of extending in the vertical direction, and the upper side and the lower side are open, respectively.

A boss 533 coupled to the outer shaft 9 is formed in the upper housing 53 , and the upper side of the accommodation space is opened by the boss 533 . The upper housing 53 includes a housing body 531 forming an inner circumferential surface surrounding the ring gear 84, and a lower flange 522 extending outward from the open lower side of the housing body 531 in a radial direction to be coupled and an upper flange 532 , the boss 533 extending upwardly from the housing body 531 .

The sun gear 81 is connected to the drive shaft 10a and rotates integrally with the drive shaft 10a. In the embodiment, the sun gear 81 is a helical gear, and correspondingly, the pinion gear 82 and the ring gear 84 are also configured to have teeth in the form of a helical gear, but the present invention is not limited thereto. For example, the sun gear 81 may be formed of a spur gear, and the pinion gear 82 and the ring gear 84 may also have teeth in the form of spur gears.

The ring gear 84 may be fixed in (or relative to) the housing body 531 . That is, the ring gear 84 is rotated integrally with the gear housing 5 . The ring gear 84 has teeth formed on the inner circumferential surface defining the ring-shaped opening.

The pinion gear 82 is interposed between the sun gear 81 and the ring gear 84 , and meshes with the sun gear 81 and the ring gear 84 . A plurality of pinion gears 82 may be disposed along the circumference of the sun gear 81 , 82(1), 82(2), 82(3), and 82(4), each pinion gear 82. is rotatably supported by the carrier 83 .

The carrier 83 is coupled (shafted) with the inner shaft 4 . The carrier 83 is a kind of link connecting the pinion gear 82 and the inner shaft 4 . That is, as the pinion gear 82 revolves around the sun gear 81 , the carrier 83 rotates, and the inner shaft 4 rotates accordingly.

The carrier 83 includes an upper plate portion 831 formed with a boss 831a coupled to the inner shaft 4, and a lower plate portion 832 spaced downward from the upper plate portion 831 and having a through hole through the central portion through which the driving shaft 10a passes. ) and a gear shaft 833 connecting the upper plate portion 831 and the lower plate portion 832 . A plurality of gear shafts 833 are provided along the circumferential direction, and a pinion gear 82 may be installed on each gear shaft 833 .

The gear shaft 833 is rotatably installed with respect to the upper plate part 831 and/or the lower plate part 832 , so that the pinion gear 82 and the gear shaft 833 can rotate together. Alternatively, rotation of the gear shaft 833 may be constrained, and the pinion gear 82 may be rotated relative to the gear shaft 833 .

The boss 831a formed in the upper plate portion 831 is located in the boss 533 formed in the upper housing 53 described above, and the bearing 32 may be interposed between the boss 831a and the outer shaft 9 .

Hereinafter, with reference to FIG. 4, the operation|movement of the clutch 6 is demonstrated.

Fig. 4(b) shows a state in which the clutch 6 has reached the maximum rising position. In this state, when the inner shaft 4 rotates in the forward direction, the clutch 6 can no longer rise, so that the outer shaft 9 rotates in the forward direction. This is a case in which the pulsator 3 and the inner tank 2 are rotated together in the forward direction.

Conversely, when the inner shaft 4 is rotated in the reverse direction when the clutch 6 has reached the maximum rising position, the clutch 6 is lowered. When the driving shaft 10a is rotated in a state where the clutch 6 is positioned between the maximum rising position and the maximum falling position, the rotation of the outer shaft 9 may be induced depending on the load or inertia of the inner tank 2 . That is, when the load acting on the outer shaft 9 from the inner tank 2 is sufficiently large, the outer shaft 9 maintains a stationary state and only the inner shaft 4 rotates, but the load may constrain the rotation of the outer shaft 9 . If not, the outer shaft 9 may be rotated in the opposite direction to the inner shaft 4 .

Fig. 3(a) shows the operation of the planetary gear train when the drive shaft 10a is rotated in the reverse direction and the clutch 6 is lowered. Assuming that the rotation of the ring gear 84 is constrained, it can be seen that when the driving shaft 10a rotates at an angular velocity W1 , the carrier 83 rotates in the same direction as the driving shaft 10a at an angular velocity W3 . (W1>W3)

On the other hand, depending on the maximum angle (or the number of revolutions) at which the clutch 6 can continuously rotate between the maximum descending position and the maximum ascending position, the pulsator 3 is continuously rotated while the inner tank 2 is stopped. The maximum possible angle (or number of rotations) may be determined.

In the section in which the clutch 6 is raised and lowered, the pulsator 3 may be rotated in a forward direction or a reverse direction according to the rotation direction of the motor 10 . That is, in particular, when the clutch 6 does not reach the maximum rising position or the maximum falling position and is between these positions, the rotation direction of the pulsator 3 is also determined according to the rotation direction of the inner shaft 4, By controlling the rotation direction of the motor 10, it is possible to induce the stirring rotation of the pulsator (3).

Fig. 4(a) shows a state in which the clutch 6 has reached the maximum lowering position. In this state, when the inner shaft 4 rotates in the reverse direction, the clutch 6 can no longer descend, so the outer shaft 9 also rotates in the reverse direction. This is a case in which the pulsator 3 and the inner tank 2 are rotated in the opposite direction together.

3 (b) shows when the clutch 6 reaches the maximum descending position, the drive shaft 10a continues to rotate in the reverse direction, that is, when the pulsator 3 and the inner tank 2 are rotated together. is shown, it can be seen that both the carrier 83 and the ring gear 84 are integrally rotated in the same direction as the drive shaft 10a (ie, at the same angular velocity).

5 shows positions referenced for clutch position control. 6 is a block diagram illustrating a control relationship between main parts of a washing machine according to an embodiment of the present invention. 7 is a flowchart illustrating a method for controlling a washing machine according to an embodiment of the present invention. 8 shows the positions of the clutch in the process of initializing the position of the clutch. 9 shows detailed steps constituting the reference position alignment step. Hereinafter, a method of controlling a washing machine according to an embodiment of the present invention will be described with reference to FIGS. 5 to 9 .

According to the rotation method of the pulsator 3 and the inner tank 2, it is divided into an agitating mode and a spin mode. In the stirring mode, the motor 10 is driven in a state in which the connection between the inner shaft 4 and the outer shaft 9 is released, and the clutch 6 is positioned between the maximum rising position and the maximum falling position. In the stirring mode, when the load acting on the outer shaft 9 is large because laundry or water is sufficiently contained in the inner tub 2 , only the pulsator 3 is rotated while the inner tub 2 is stopped. However, when the load acting on the outer shaft 9 is not sufficient to keep the inner tank 2 in a stationary state, the outer shaft 9 is opposite to the inner shaft 4 by the torque transmitted through the planetary gear train 8 . rotated in the direction

In the stirring mode, the pulsator 3 can be rotated alternately in both directions by repeatedly switching the rotational direction of the motor 10 . The agitation mode is mainly used to evenly distribute the cloth put into the inner tub 2 or to perform washing or rinsing while the inner tub 2 is filled with water.

In the spin mode, the motor 10 is driven while the inner shaft 4 and the outer shaft 9 are connected. In the spin mode, the clutch 6 is located at the maximum rising position or the maximum falling position. In the spin mode, the pulsator 3 and the inner tank 2 are rotated together in the same direction. The spin mode is mainly used for spin-drying, but is also used to create a rotating water flow during washing or rinsing.

On the other hand, in the stirring mode, the clutch 6 is raised or lowered according to the rotation direction of the motor 10. At this time, the rotation of the motor 10 must be controlled so that the clutch 6 does not reach the maximum rising position or the maximum falling position. do. This is because, when the motor 10 continues to rotate in the same direction when the clutch 6 reaches the maximum rising position or the maximum falling position, it enters the spin mode.

When the clutch 6 reaches the maximum rising position or the maximum falling position even for a moment, the clutch 6 can no longer rotate relative to the inner shaft 4 and takes the torque for rotating the outer shaft 9 . Such a load applied to the clutch 6 is unnecessary in the stirring mode and not only adversely affects the durability of the clutch 6, but also the noise generated by the clutch 6 colliding with the upper stopper or the lower stopper is also not good. . Therefore, in the stirring mode, it is necessary to prevent the clutch 6 from reaching the maximum rising position or the maximum falling position in advance, or if such a situation occurs unintentionally, it is necessary to quickly grasp this and stop the driving of the motor 10 . there is In this regard, a more detailed description will be given of a method for controlling a washing machine according to an embodiment of the present invention.

P1 to P6 shown in FIG. 5 indicate the position of the clutch 6, P1 is the maximum descending position, P2 is the lower allowable position, P3 is the lower starting position, P4 is the upper starting position, P5 is the upper allowable position, P6 is defined as the maximum ascent position. Here, each position is defined based on the upper end of the clutch 6 .

The maximum descending position P1 is the lowest point at which the clutch 6 can descend, and is the position when the clutch 6 is moved to the lowest point by the thread 41 . However, when the lower stopper is separately provided according to the embodiment, the position of the clutch 6 may be in a state in which further movement is restricted by the lower stopper.

The lower starting position (P3) is the lowest position of the clutch 6 in the stirring mode, and the upper starting position (P4) is the position where the clutch 6 is highest in the stirring mode. That is, in the stirring mode, the control unit 91 rotates the motor 10 in the forward/reverse direction alternately to raise/lower the clutch 6, and the clutch 6 moves the lower start position P3 and the upper start position P4. ) to control the elevation between the

When defining the stirring control section (ST) between the lower starting position (P3) and the upper starting position (P4), the upper starting position (P4) corresponding to the upper limit of the stirring control section (ST) is the maximum rising position (P6) The lower starting position (P3) corresponding to the lower limit of the stirring control section (ST) is spaced upward by a preset second distance from the maximum descending position (P1).

The lower allowable position (P2) is a position determined between the maximum descending position (P1) and the lower starting position (P3), and the upper allowable position (P5) is determined between the upper starting position (P4) and the maximum ascending position (P6). is the location

The maximum rising position P6 is the highest point at which the clutch 6 can rise, and is a position when the clutch 6 is moved to the highest point by the thread 41 . However, when the upper stopper is separately provided according to the embodiment, the position of the clutch 6 may be in a state in which further elevation is restricted by the upper stopper.

On the other hand, when the stirring mode is started (S1), a step of initializing the position of the clutch 6 (S2, initialization step), and agitating the pulsator 3 while controlling the position of the clutch 6 within a preset range step (S3, stirring washing step) is carried out in sequence.

The initialization step (S2) includes a reference position alignment step (S21) of rotating the motor 10 in the first direction to align the clutch 6 to a reference position, and a starting position by moving the clutch 6 from the reference position. It includes a starting position alignment step (S22) to align with. (Refer to the process from (a) to (b) of FIG. 8.)

First, the reference position alignment step (S21) will be described. The reference position is a predetermined one of the maximum rising position (P6) and the maximum falling position (P1). Hereinafter, it is assumed that the reference position is the maximum descending position P1, and in this case, the first direction is the reverse direction (the direction in which the motor 10 is rotated so that the clutch 6 is lowered). According to an embodiment, when the reference position is set as the maximum ascending/lowering position P6, the first direction is a forward direction (a direction opposite to the reverse direction).

The controller 91 controls the motor 10 to rotate by _{a preset reference alignment angle θ a in the reverse direction.} The rotation control of the motor 10 may be performed based on _{the position θ m} of the rotor 11 detected from the position detector 94 .

The reference alignment angle θ _a is set according to the displacement of the clutch 6 from the maximum rising position P6 to the maximum falling position P1 . When the pitch interval of the threads 41 formed on the inner shaft 4 is constant, the motor 10 is rotated in the reverse direction by the reference alignment angle θ _{a while the clutch 6 is in the maximum rising position P6} , the clutch 6 is lowered to the maximum lowering position P1. That is, when the displacement of the clutch 6 becomes the maximum (that is, the distance between the maximum rising position P6 and the maximum falling position P1), the motor 10 rotates by the reference alignment angle θ _{a in one direction.} do.

When the clutch 6 is located at an arbitrary point on the inner shaft 4 and the motor 10 is controlled to rotate _{by the reference alignment angle θ a in the first direction by the control of the control unit 91, the clutch} (6) is aligned with the reference position (P1). The speed control system controls _{the rotation of the motor 10 to follow the command speed ω m} ^* applied by the control unit 91 , wherein the control unit 91 controls the position θ detected from the position detector 94 . _m ) based on the control of the rotation of the motor (10).

However, the case where the driving of the motor 10 is started while the clutch 6 is in the maximum rising position (P6, in the case where the maximum rising position P6 according to the embodiment is the reference position, the maximum falling position P1) Unless otherwise, the motor 10 cannot rotate all of the reference alignment angle θ _{a .} That is, in most cases, the clutch 6 reaches the maximum lowering position P1 before the rotation of the motor 10 reaches the reference alignment angle θ _{a .} Therefore, in the reference alignment step S21, when the clutch 6 reaches the initial position, it is necessary to brake the motor 10 even if _{the rotation of the motor 10 is not made as much as the reference alignment angle θ a .}

The control unit 91 may determine whether the clutch 6 has reached the maximum lowering position P1 based on the current of the motor 10 . Specifically, the controller 91 controls the inner shaft 4 to rotate in the reverse direction when the current value (I _dc ) of the motor 10 is greater than or equal to the preset first current value (I ₁ ), the clutch 6 is maximally lowered. It is determined that the position P1 is reached and the rotation of the motor 10 can be stopped.

When the clutch 6 reaches the maximum descending position P1 and the inner shaft 4 and the outer shaft 9 are connected, the current value I _dc is also sharply increased due to a sudden increase in the load applied to the motor 10 . Therefore, when the current value (I _dc ) at this time is equal to or greater than the first current value (I ₁ ), the control unit 91 determines that the clutch 6 has reached the maximum descending position P1 and brakes the motor 10 . can do. In particular, even when the rotation _{of the motor 10 does not reach the reference alignment angle θ a} , the time required for initialization of the clutch 6 can be shortened by braking the motor 10 .

On the other hand, depending on the load conditions acting on the motor 10, at the start of the start (that is, _{from the time when the current I dc} is applied to the motor 10 in a stopped state until a certain time elapses), the clutch 6 ) is not in the maximum falling position (P1), the current value (I _dc ) may become the first current value (I ₁ ). That is, since the load applied to the pulsator 3 is large, a current greater than _{the first current value (I 1 ) is sometimes required to start the motor 10 in a stopped state.}

Therefore, it is preferable that a large current value generated at the beginning of the start-up should be excluded in determining the position of the clutch 6, and in this aspect, the control unit 91 initiates the rotation of the inner shaft 4 in the reverse direction in the first The rotation of the motor 10 may be controlled to stop based on _{the current value I-dc} of the motor 10 sensed after the set time T _{1 has elapsed. That is, when the detected current value (I dc} ) is greater than or equal to the first current value (I ₁ ) after the first set time (T1) has elapsed after the motor 10 is started, the braking of the motor 10 is performed will be.

On the other hand, according to the embodiment, the control unit 91 is _{the current value (I dc} ) of the motor 10 at the _{initial start (that is, within the second set time (T 2 ) after the motor 10 starts to rotate in the reverse direction)} When the second current value I ₂ , the third current value I ₃ , and the fourth current value I ₄ are sequentially detected, it is determined that the clutch 6 has reached the maximum descending position P1, Even when the rotation of the motor 10 does not reach the _{reference alignment angle θ a , the motor 10 may be braked.}

The second current value I ₂ corresponds to a current value when the motor 10 starts starting. When the motor 10 is started, a significant amount of current is applied to the motor 10 because the stop inertia of the pulsator 3 must be overcome, and the current value at this time may be the second current value (I ₂ ). .

The third current value I ₃ corresponds to the current value when the clutch 6 reaches the reference position and the inner shaft 4 and the outer shaft 9 are connected. Internal shaft 4 and the outer shaft 9 is connected when the is due to the rapid increase in the load on the motor 10 increases to too sudden current value (I _dc), the current value at this time (I _dc) is the third current value (I ₃ ) can be

The fourth current value I ₄ corresponds to a current value when the inner shaft 4 and the outer shaft 9 are integrally rotated in a connected state. That is, the fourth current value I ₄ is the motor 10 in a state in which the clutch 6 reaches the reference position (the maximum descending position P1 in the embodiment) and the inner shaft 4 and the outer shaft 9 are connected. _{It is set based on the current value (I dc} ) when the continuous rotation in the reverse direction, in particular, it is preferably determined based on _{the current value (I dc} ) when the rotation of the outer shaft (9) is started.

In this way, when the second current value I ₂ , the third current value I ₃ , and the fourth current value I- ₄ are sequentially detected within the second set time T ₂ , the clutch 6 . The motor 10 is started in a state that is separated from the maximum descending position P1 within a distance corresponding to the second set time T ₂ , and the position of the clutch 6 is the maximum within _{the second set time T 2 ).} It corresponds to a case where a series of processes in which the lowering position P1 is reached and then the rotation of the outer shaft 9 is started is carried out. Here, as the second set time (T ₂ ) is set shorter, the series of current values detected as above start to descend from the location where the clutch 6 is close to the reference position at the start time of the motor 10, and the reference It is an indicator to judge that the position has been reached.

That is, the control unit 91 based on a series of current values detected as above (I ₂ , I ₃ , I ₄ ), the initial position of the clutch 6 is close to the maximum descending position (P1), so that the motor 10 ), it can be determined that the clutch 6 is already aligned to the maximum descending position P1 before the rotation reaches the reference alignment angle θ _{a .} Therefore, when the clutch 6 reaches the maximum descending position P1 before the rotation of the motor 10 reaches the reference alignment angle θ _a , the rotation of the motor 10 by the remaining angle is omitted by the clutch 6 ) can shorten the time it takes to initialize the position.

After the clutch 6 is aligned to the reference position, the starting position alignment step S22 is performed. The starting position alignment step (S22) is a step of moving the clutch 6 from the reference position and aligning it to a preset starting position. (Refer to the process from (b) to (c) of FIG. 8.)

The control unit 91 controls the rotation of the motor 10 _{by the starting alignment angle θ b} so that the clutch 6 moves from the starting position to the target position corresponding to the other one of the upper and lower limits of the stirring control section ST. Control. When the starting position is the lower limit (P3) of the stirring control section (ST) and the target position is the upper limit (P4) of the stirring control section (ST), the motor 10 rotates in the forward direction by the starting alignment angle (θ _b ) On the contrary, when the starting position is the upper limit (P4) of the stirring control section (ST) and the target position is the lower limit (P3) of the stirring control section (ST), the motor 10 moves in the reverse direction at the starting alignment angle θ _b ) is rotated.

Here, the starting alignment angle θ _b is the clutch 6 moving from the lower end P3 to the upper end P4 of the stirring control section ST (or moving from the upper end P4 to the lower end P3) during) the angle at which the motor 10 is rotated. Since the lower end P3 and the upper end P4 of the stirring control section ST are predetermined, the starting alignment angle θ _b set corresponding to the distance between these positions is also a predetermined value.

The controller 91 determines whether the rotation angle θ _m of the rotor has reached the starting alignment angle θ _{a based on the position θ m} detected from the position detector 94, and when it is determined that it has reached The motor 10 may be braked. After the motor 10 is stopped by braking, the stirring washing step (S3) may be performed.

In the stirring washing step (S3), the inner shaft 4 is alternately rotated in both directions in a state in which the connection between the inner shaft 4 and the outer shaft 9 is released. In the stirring washing step (S3), the control unit 91 controls the rotation of the motor 10 so that the clutch 6 does not reach either the maximum lowering position P1 or the maximum raising position P6.

Specifically, the control unit 91 is a target position corresponding to the other one of the upper and lower limits of the stirring control section ST from the starting position P3 (in the embodiment, the upper starting position P4, or the starting position is the upper starting position) In the case of the position (P4), the target position is the lower starting position (P3).) The rotation of the motor 10 is controlled so as to be rotated _{by the stirring control angle θ d corresponding to the displacement.}

Here, since the lower start position P3 and the upper start position P4 are preset, the motor to be rotated in order to move the clutch 6 by the distance between the lower start position P3 and the upper start position P4. _{The stirring control angle (θ d} ) of the rotor of (10) is also predetermined. The control unit 91 controls the _{motor 10 to rotate in the forward direction (second direction) by the stirring control angle θ d} , and then the clutch 6 moves from the upper start position P4 to the lower start position P3 . The motor 10 may be rotated in the reverse direction (first direction) by the stirring control angle θ _{d to return.} These processes are repeated a plurality of times, the pulsator 3 can be rotated repeatedly in the forward / reverse direction.

By the way, since the rotation direction of the motor 10 _{is made based on the position (θ m} ) of the rotor detected by the position detector 94 as described above, the rotation angle of the rotor detected by the position detector 94 . When the _{motor 10 is braked after (θ m} ) reaches the stirring control angle (θ _d ), the motor 10 is completely stopped by rotational inertia until it is completely stopped immediately. will be rotating

_{Alternatively, by braking the motor 10 at a point in time when the rotation angle θ m} detected by the position detector 94 does not reach the stirring control angle θ _d , the motor 10 is stopped at a time point where the motor 10 is stopped. A method of controlling the total rotation angle considered up _{to reach the stirring control angle (θ d} ) may also be considered, but in this case also, the time when the braking of the motor 10 starts is when the motor 10 is completely stopped. Since it is determined by predicting the state in advance, the distance that the clutch 6 moves until the motor 10 is temporarily stopped in the course of direction change tends to have some deviation.

In either case, the position where the clutch 6 is temporarily stopped in the course of changing the direction is deviated from the lower starting position P3 to the lower side by a certain distance or more (when the rotation of the motor 10 is converted from the reverse to the forward direction), or the upper When it deviates upward from the starting position P4 by a certain distance or more (when the rotation of the motor 10 is switched from the forward direction to the reverse direction), that is, the control of the movement distance of the clutch 6 cannot be performed within the allowable range. In this case, there is a fear that the clutch 6 may reach the reference position (that is, the maximum descending position P1 or the maximum ascending position P6).

In order not to cause such a problem, it is the lower allowable position P2 and the upper allowable position P5 that set the allowable limits for the displacement of the clutch 6 . That is, preferably, while the rotation direction of the motor 10 is switched in the stirring mode, the lowering of the clutch 6 is allowed up to the lower allowable position P2, and the raising of the clutch 6 is allowed at the upper allowable position P5. need to be allowed up to.

The control unit 91, while the stirring washing step (S3) is carried out, _{based on the position (θ m} ) detected from the position detector 94, the clutch 6 is at the lower allowable position (P2) or the upper allowable position (P5) ) is reached (S4), and if it is determined that it has arrived, that is, if it is determined that the clutch 6 is out of the control range (that is, the section between the lower allowable position P2 and the upper allowable position P5) , the motor 10 may be braked.

After the stirring mode is started, when the preset stirring washing time (Tset) is reached, the stirring mode is terminated (S5, S6).

Alternatively, the control unit 91 controls the clutch 6 in a state initially aligned to the starting position P3 or P4 at the time point at which the stirred washing step S3 is performed while the stirred washing step S3 is performed. When a preset continuous driving time elapses from the time when the motor 10 is started to move to the target position (P4 or P3), it is also possible to configure the reference position alignment step (S21) to be performed again. After that, if the stirring washing time (Tset) has not arrived, the starting position alignment step (S22) and the stirring washing step (S23) are sequentially performed again, and the continuous driving is performed again after the stirring washing step (S23) is started each time. When the time arrives, the reference position alignment step (S21), the starting position alignment step (S22) and the stirring washing step (S23) may be performed. These steps are continued after the stirring washing step (S3) is started until the stirring washing time (Tset) arrives.

In the above, preferred embodiments of the present invention have been shown and described, but the present invention is not limited to the specific embodiments described above, and in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Various modifications may be made by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

Claims (6)

In the hollow formed on the outer shaft for rotating the inner tank, the inner shaft for rotating the pulsator is located, and a clutch screwed with the inner shaft and spline-coupled to the outer shaft in the hollow is provided, the clutch by forward rotation of the inner shaft When is lifted and reaches the preset maximum ascending position, further upward movement is stopped, the outer shaft rotates in the forward direction, and the inner shaft rotates in the reverse direction when the clutch reaches the preset maximum descending position, further lowering of the outer shaft is stopped. In the control method of the washing machine rotating in the reverse direction,
Including a stirring mode in which the pulsator is relatively rotated with respect to the inner tank and a spin mode in which the pulsator and the inner tank are integrally rotated,
The stirring mode is,
(a) rotating a motor for driving the inner shaft in a first direction to align the clutch to a reference position corresponding to any one of the maximum descending position and the maximum ascending position;
(b) rotating the motor in the second direction by a preset starting alignment angle to align the clutch from the reference position to a starting position corresponding to any one of the upper and lower limits of the preset stirring control section, the stirring control section The upper limit of the step is spaced downward by a first distance from the maximum ascending position, and the lower limit (P3) of the stirring control section is spaced upward by a second distance from the maximum descending position; and
(c) by the stirring control angle set according to the displacement of the clutch from the starting position to the target position so that the clutch moves from the starting position to the target position corresponding to the other one of the upper and lower limits of the stirring control section Controlling the rotation of the motor,
The spin mode is
At least one step of rotating the motor in the forward direction when the clutch is located in the maximum rising position and rotating the motor in the reverse direction when the clutch is located in the maximum downward position How to control washing machine. The method of claim 1,
The stirring mode is,
(d) controlling the rotation of the motor so that the clutch returns from the target position to the starting position. 3. The method of claim 2,
Steps (c) and (d) are repeated a plurality of times. 4. The method of claim 3,
While steps (c) and (d) are repeatedly carried out, if it is detected that the clutch has reached a preset allowable position outside the stirring control section, the control method of a washing machine to perform step (a) again. The method of claim 1,
The step (a) is,
and controlling the motor to rotate in the first direction at a reference alignment angle set according to displacement of the clutch between the maximum rising position and the maximum falling position. The method of claim 1,
In the spin mode, the motor rotates more than a reference alignment angle, wherein the reference alignment angle is set according to a displacement of the clutch between the maximum rising position and the maximum falling position.

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